This invention relates to localized radiation heating and more particularly to localized heating in microwave appliances.
In microwave heating, it can be desirable to provide localized surface heating to achieve such effects as browning and crisping. While the typical microwave oven is a suitable energy source for uniform cooking, it is not satisfactory for selective heating effects, such as browning and crisping. In fact, the typical microwave arrangement produces the cooking in which the external surface of the cooked material, particularly if desired to be crispy, tends to be soggy and unappetizing in appearance.
One attempt to provide suitable browning and crisping of microwave cooked foods has been by the selective use of virtually transparent, thin metallized aluminum coatings. Such material can produce heat and provide the desired crisping. The difficulty with this thickness of metal is that it can produce arcing and defeat the microwave operation.
Another attempt to provide the desired heating effect has been by the suggested use of carbon black coatings. These do not produce arcing but are generally found to be unsatisfactory because they produce a run-away heating effect.
Accordingly, it is an object of the invention to facilitate the selective radiation heating of objects, particularly food. A related object is to improve the taste and texture of microwave heated foods. Another object is to maintain the wholesomeness and nutritional value of food.
A further object of the invention is to overcome the disadvantages experienced in the use of thin metallic coatings in attempting to supply a supplemental heating effect in microwave cooking.
Still another object of the invention is to overcome the disadvantages that have been experienced in obtaining localized heating effects. A related object is to overcome the difficulties that have prevented carbon black coatings from being used for localized heating.